Bessel beam

About: Bessel beam is a research topic. Over the lifetime, 1946 publications have been published within this topic receiving 42264 citations.

Deep Seated Negative Axicon in Selective Optical Fiber Tip and Collimated Bessel Beam

Abstract: In this letter, we have demonstrated the fabrication of a deep seated negative axicon (DSNA) with micrometer dimensions inside a selective optical fiber tip for the generation of optical Bessel beams (BBs). The DSNA is prepared by simple chemical etching of the fiber tip in hydrofluoric acid under the influence of capillary action. The selective optical fiber has a high numerical aperture of 0.3 and a small core diameter of about $4~\mu \text{m}$ . The higher etching rate of the optical fiber core contributes to fabricate the DSNA, which converts Gaussian-like beam into BB. The central spot of the BB shows quasi-invariant spot-size over the propagation distance of sub-millimeter and centimeter range. The self-protected DSNA can be useful for scanning optical fiber endoscopy applications as well as can be integrated into systems, where non-diffracting BB is preferred.

Propagation of Bessel beams generated using finite-width Durnin ring.

Abstract: We have studied the increase of the power contained in Bessel beams generated using the Durnin ring technique, which is compatible with microelectromechanical systems technology. Increasing the ring width to increase the output power will lead to deviation from the Bessel beam profile and its diffraction properties. In this work, the effect of the ring width on the generated beam is investigated. An analytical expression for the generated beam depth of focus (DOF) is obtained. A Fourier optics model is also developed to estimate the transverse field profile. The theoretical predictions are assisted by numerical simulations and experimental measurements. The developed models allow engineering the beam diffraction properties to make the necessary compromise between the DOF and the amount of energy carried by the beam depending on the targeted application.

Dielectric lens guides in-plane propagation of surface plasmon polaritons.

Abstract: In this work, we present in-plane propagation of surface plasmon polaritons (SPPs) guided by a single dielectric (Al2O3) subwavelength lens. By mounting a designed Al2O3 nanoparticle on the silver film, the effective index of a silver-Al2O3 interface is influenced by the particle thickness, then the phase difference between the silver-air and silver-Al2O3 interface can be utilized to modulate the in-plane propagation of SPPs. We show that an elliptical Al2O3 lens transforms the diffusive SPPs into a collimated beam, whose direction of propagation and beam width can be easily controlled. We also present that a triangular Al2O3 lens significantly reforms the SPPs to a Bessel beam, which possesses non-diffractive and self-healing properties. Our investigation provides unique way to guide the in-plane transport of SPPs by using dielectric subwavelength elements, which may achieve potential applications in plasmonic integrated circuits.

Gaussian-to-Bessel beam transformation using a split refracting system

Abstract: A two-element refracting system is designed to transform a Gaussian laser beam into a diffraction-free Bessel beam. The resulting input and output surfaces are almost spherical, which makes for easy implementation of the system.